Bird Note: South Polar Skuas - Bullies of the Oceans
The bird world has its bullies, too.
with Tom Johnson
Meet the South Polar Skua, a big, bad bully of the bird world. During summer in Antarctica, South Polar Skuas feed their young with the chicks of other seabirds. And once their breeding season ends, the skuas fly to northern oceans, such as the North Atlantic, to find large flocks of shearwaters, gulls, or terns – then they steal the food that their fellow seabirds worked so hard to catch!
Seals, whales, penguins and other animals eat Antarctic salps as a part of their diet. But, what is a salp, you ask? Salps are filter-feeding tunicates—transparent and gelatinous animals that float throughout the water column.
… among the very coolest of the fishes. You might say they have icewater in their veins. That would be inaccurate, though.
The antifreeze compounds in their blood prevent it from icing up. One thing they don’t seem to need in it, though: haemoglobin. It probably helps that there’s so much oxygen dissolved in the near-freezing water of the Southern Ocean- nearly twice as much as in the tropics.
They did need a few other tools, though, to dispense with the oxygen-binding protein. They have a larger volume of blood then you’d expect for their size, and a larger heart. Also, more blood vessels in their gills than you see in other fishes.
Explore the world’s new coastlines if sea level rises 216 feet…
The maps here show the world as it is now, with only one difference: All the ice on land has melted and drained into the sea, raising it 216 feet and creating new shorelines for our continents and inland seas.
There are more than five million cubic miles of ice on Earth, and some scientists say it would take more than 5,000 years to melt it all. If we continue adding carbon to the atmosphere, we’ll very likely create an ice-free planet, with an average temperature of perhaps 80 degrees Fahrenheit instead of the current 58…
The Antarctic Peninsula is one of the fastest-warming places on Earth, and the increasing temperature has had one unusual impact: Moss is growing up to four times more quickly than it did a century ago, new research shows. The number of predatory microbes inside the moss, named amoebae, has also swelled with the temperature, increasing more than sixfold since the area began to warm in the 1960s.
Moss and microbes may not be the first life-forms that come to mind when thinking of the Antarctic, but they are the dominant land-based organisms that live in the area year-round, surviving frigid temperatures, said Jessica Royles, a researcher at the British Antarctic Survey and the University of Cambridge. The study “highlights that biological systems there are sensitive to changes in climate that we know have occurred, but haven’t necessarily measured in these systems,” Royles told LiveScience…
Deep, dark, and mysterious, Lake Vostok is one of the deepest subglacial lakes in the world.
Buried under more than 2 miles (3.7 kilometers) of ice near Vostok research station in Antarctica, the lake filled before Antarctica froze 15 million years ago, researchers think. Covered with ice for millennia, cut off from light and contact with the atmosphere, Lake Vostok is one of the most extreme environments on Earth.
The freshwater lake may harbor a unique ecosystem of microbes and other creatures that evolved in isolation for hundreds of thousands of years. These “extremophiles" could mimic life on other moons and planets, such as Jupiter’s icy moon Europa. Only meltwater from the overlying icesheet and drainage from Antarctica’s subglacial waterways have touched the lake since it froze over during the Miocene period. This constant replenishment means the water in the lake may be only as old as the ice that melts to form it, some 700,000 to 800,000 years, according to ice cores. But the true age of the lake water is unknown…
Cystosphaera jacquinotii, a fucoid alga native to the Antarctic peninsula. The spherical structures are pneumatocysts, or floats which keep the lamina elevated in the water column and exposed to light. The clustered fingerlike projections are receptacles, which contain reproductive structures (antheridia and oogonia). Not a kelp!
The Shy Albatross, Thalassarche cauta, ranges extensively across the Southern Ocean. It spends the majority of its life at sea, soaring on strong winds, or resting on the water’s surface. It feeds on fish, squid and crustaceans, plucked from the ocean, and will often gather in flocks behind fishing vessels to scavenge.
Another Look at the Changes on the Antarctic Sea Floor
What scientists thought would take centuries to occur is taking place in just a matter of years. “…populations of glass sponges have tripled between 2007 and 2011, allowing them to completely take over the seafloor.”
In the frigid, inky ocean depths beneath permanent ice shelves, life tends to move pretty slowly. But a recent expedition to the seafloor under a newly thawed Antarctic ice sheet has revealed an unexpected invertebrate invasion. Some of Earth’s strangest species, a group of ghostly pale sponges made of glass, have set up shop there in a hurry, upending much of what scientists know about these exotic creatures.
Thanks to changes in this ecosystem brought on by a warming climate, these gardens of glass sponges have sprouted up in only a few years, a veritable population explosion for species once thought to take decades or centuries to spread. It suggests that glass sponges could find themselves squarely on the winner’s podium when it comes to climate change.
In 2011, a team led by researchers from the Alfred Wegener Institute for Polar and Marine Research completed a new census of glass sponge growth on the seafloor underneath the Larsen Ice Shelf in Antarctica’s Weddell Sea, following up on a similar survey done in 2007. Their surprising results were published today in Current Biology…
…is a large species of amphipod that is native to the waters of the eastern Antarctic Ocean. E.rubrieques is an opportunistic feeder and has been observed both scavenging and showcasing predatory behavior. It has been mostly observed on surfaces but is is known to be a motile epibenthic swimmer as well (meaning it rarely swims).This species was recently discovered and much of its biology and ecology still remains unknown.
…is a species of nermertean (ribbon) worm that is found in Antarctic and Southern Atlantic waters. P.corrugatus is both a scavenger and a predator and will feed on diatoms, arthropods, molluscs, sponges and various other invertebrates. It dispatches these prey items by shooting its extremely long barbed proboscis at them. It can also use this proboscis for defense purposes as-well. However, it relies mostly on its acidic mucus to deter predators.
P.corrugatus can grow quite long and individuals over six feet have been observed. Normally an animal this long would not be able to breathe through its skin but P.corrugatus has a low metabolism and can flattern/elongate its body to aid in the uptake of oxygen.
The Cape Petrel (Daption capense) is a seabird common to the Southern Ocean. The species are aggressive eaters which feeds mostly on crustaceans, although they are also known to eat fish, squid, and edible waste. When feeding they may spit their stomach oil at competitors.
Adults reach 2.6 m in length and weigh an estimated 200-300 kg. Neonates are thought to be at least 1.1 m and 20-40 kg. The mean age of sexual maturity in females varies from 2.5 to 4.2 years and these variations may be related to changes in food abundance. Births occur mainly during the second half of October.
The distribution of crabeater seals is tied to seasonal fluctuations of the pack ice. They can be found right up to the coast of Antarctica, as far south as McMurdo Sound, during late summer ice break-up. They occur in greatest numbers in the seasonally shifting pack ice surrounding the Antarctic continent. As vagrants they travel as far north as New Zealand and the southern coasts of Africa, Australia, and South America.
Crabeater seals feed primarily on Antarctic krill, Euphausia superba and 95% of their diet is made up of this species. Small amounts of fish and squid are also part of the diet. All of the post-canine teeth are ornate, with multiple accessory cusps that interlock to form a network for straining krill from the seawater. A ridge of bone on each mandible fills the gap in the mouth behind the last upper post-canine teeth and the back of the jaw, which helps prevent the loss of krill from the mouth when feeding. Crabeater faeces are routinely a pinkish red, from their krill diet and reddish stains are frequently seen on the ice near where they are hauled-out…